Value depends on appearance, mechanical condition, and location. It appears to be a U-18. They can be had for $60 needing work, and very clean ones with no rust that have been reconditioned can fetch low $300s in NYC. The touring bar models bring more money than the drop bar editions.

The above example has a non-standard stem as it is way higher than normal. The tires look tired (no pun intended), but can't judge wheel condition. They appear to be high flange Normandy hubs with chromed steel rims, which would be original.

Frame paint looks clean.

Without additional detail that bike could easily be valued at $100-$125 for a bike restorer or about $150-$225 if the tires are okay and it is ready to ride.

Some BF members may scare you off about expensive non-conventional French parts. But frankly, there are so many vintage Peugeots out there, they do last and last. My advice if it scares you, do what Jaguar vehicle owners do; own two, one to drive and one for parts!

I have reconditioned a lot of Peugeots and U-18's in particular and they always turn out nice and the buyers are pleased. Here is one I just completed two hours ago.

UO18 Peugeot, nice paint, needs some work, $75 as is. Finished, it really depends where you live. SF or NYC, you might see pricing like above. In a more average area, $150 to $200.

Peugeots get a nice response in the marketplace. And yes, french bikes from that era had a lot of unique sized parts that have been obsolete for about 30 years. Some reproduction parts have been made, and a french parts bike is a nice option. I usually keep one or two french bikes solely for parts.